My parents visited me last week (Hi Mom!). On Sunday we struck out for London, so that they could see West End shows, eat at fancy restaurants, and attend tennis tournaments. Apparently, the near constant threat of a cycle collision in central Cambridge was not enough drama to sustain them on their trip to the UK.

We also went to Ely, where we saw this spectacular rainbow.

After a somewhat convoluted journey into the city, which involved driving to Heathrow, returning a rental car, taking a shuttle to Terminal 2, taking the Picadilly line to King’s Cross, purchasing a return train ticket, then taking the train to the West End for lunch, we were finally ready to see some of the city. While my mother watched a show, my father and I spent two hours walking around Green Park (very little) and Hyde Park (very big) to take in the sights.

Though the weather was chilly, I was excited to observe some of the local urban fauna.

Real talk: when I stopped to take this photo of a goose a pigeon LANDED ON MY ARM! It did not poop on me, but it had poop on its claws, and I am never going near a bird feeding area in London ever again, let me tell you.

I was especially tickled by the confident strut of this Egyptian Goose (don’t worry, I too had to look up the species name).

As the light was fading* it was time to walk back through the Wellington Arch and catch the tube back to King’s Cross.

I was sad to leave my parents (mainly because they were staying at a fancy hotel that had a coffee room full of free pastries and cookies), but perked up once I noticed this map of the Picadilly Line while taking the tube back to King’s Cross.

Look at this cute little skeletal hand! Bonus points for the correct number of phalanges on the pollux, as well as the appropriate orientation and differentiation of the distal radius and ulna.

However, after counting the visible carpals (6), I realized two were missing. The hand is shown in dorsal view, hence no pisiform, but it took me a few toggles back and forth between the image and some anatomical drawings and x-rays to realize that the trapezium is gone.

The illustration is by artist Rob Durkin, who provides a close-up of the image on his website. My assumption is that Durkin removed it to preserve the clean lines and blank spaces between all of the bones, make for a neater image. On his website he does specify that his aesthetic entails “achieving the perfect economy of line, angle and shape to convey the idea.”

The omission could pose a problem if you’re trying to learn hand anatomy, but if you’re trying to learn hand anatomy solely with reference to subway posters there are probably larger problems at play in your life than a missing carpal. Trapezium or no, the poster was a pretty adorable way for the universe to remind me to stop gallivanting around bird-watching and get back to work!

*WHICH HAPPENS AT 4PM NOW, WHY!?!

Image Credits: X-ray hand by Rob Durkin, taken from his “Discover London Above the Picadilly Line” poster.